Syntax errors are the most basic and obvious type of programming errors. They occur when you violate the rules of the language you are using, such as missing a semicolon, a bracket, or a quotation mark. Syntax errors are usually easy to spot and correct, as most code editors and compilers will highlight them or give you an error message. However, sometimes syntax errors can be subtle or hidden, especially if you are working with complex or nested structures. To avoid syntax errors, you should always follow the coding conventions and style guides for your language, use proper indentation and formatting, and review your code carefully before running or testing it.
Syntax errors are common in programming and can occur for various reasons. To avoid them, it is crucial to define clear metrics, use delimiters correctly, and pay attention to operators. Good indentation and the use of an IDE can help identify errors. In addition, understanding the programming language and reading error messages can help correct syntax errors more quickly. Remember, practice makes perfect. The more you program, the more familiar you become with the language syntax and the less likely you are to make syntax errors.
Most of the syntax errors are generally highlighted by a good code editor. The best way to avoid syntax errors is to keep your code modular so that each part can be easily tested.
If you're new to a language, have a cheat sheet or example code snippet open in another tab to help you use the correct syntax. Official language documentation often has many small examples that can prove to be very useful in remembering the syntax.
I've found that a good Integrated Development Editor (IDE) makes it easier to spot syntax errors, highlighting common errors and pointing you in the right direction. Depending on the language, the error given when trying to compile the code may not be particularly helpful (looking at you c++). I agree with Ryan, looking at the documentation to see examples of how a part of the language can be used can be really helpful. Seeing a correct way of writing something may help you understand what mistake you've made in your own code.
Os erros de sintaxe ocorrem quando o código viola as regras gramaticais da linguagem de programação. Eles são geralmente detectados pelo compilador ou interpretador e impedem que o código seja executado. Alguns exemplos comuns de erros de sintaxe são a falta de ponto e vírgula no final de uma instrução, a má formação de uma expressão ou o uso incorreto de palavras-chave. Para evitar esses erros, é importante revisar o código em busca de erros de digitação, verificar a correspondência correta de parênteses, chaves e colchetes, e utilizar as ferramentas de verificação de sintaxe fornecidas pela sua IDE ou editor de texto. Este é um tipo de erro inaceitável.
Logic errors are more difficult to detect and fix than syntax errors, because they do not cause your code to fail or crash, but rather produce unexpected or incorrect results. Logic errors occur when you make a mistake in the design or implementation of your algorithm, such as using the wrong operator, variable, or function, or forgetting a condition or a loop. Logic errors can be very frustrating and time-consuming to debug, as they may not be apparent until you run your code with different inputs or scenarios. To avoid logic errors, you should always plan and outline your algorithm before coding, use pseudocode or comments to explain your logic, and use debugging tools or techniques to trace and test your code step by step.
Covering the code with unit tests for each piece of business logic helps you catch most of the logical errors. Make sure to add as many unit tests as required to cover all different possible edge cases.
Sometimes it's best to start your project with unit tests before writing a single line of business logic. Write your desired outcome in tests and lean on this as a structure for your code. The tests will help you write your code in a modular way with small, discrete functions whose logic is easy to understand. This way of working is often described as "test driven development", or "TDD".
I find testing gives me a lot of confidence when introducing complex logic. The tests of critical business logic should be designed with a domain specialist. Otherwise tests themselves could contain logic errors based on assumptions.
Os erros de lógica ocorrem quando o código não produz os resultados esperados devido a uma falha na formulação do algoritmo ou na sequência de instruções. Esses erros podem ser difíceis de detectar, pois o código pode ser executado sem erros, mas produzir resultados incorretos. Para evitar esses erros, é importante entender claramente o problema a ser resolvido, planejar cuidadosamente o algoritmo e testar o código com diferentes casos de entrada, verificando se os resultados estão corretos. Para evitá-lo é importante trabalhar com altos níveis de atenção e foco.
Runtime errors are the most serious and dangerous type of programming errors, because they cause your code to crash or terminate unexpectedly during execution. Runtime errors occur when you encounter a situation that your code cannot handle, such as dividing by zero, accessing an invalid memory address, or exceeding the available resources. Runtime errors can be caused by external factors, such as user input, network connection, or hardware failure, or by internal factors, such as memory leaks, buffer overflows, or infinite loops. To avoid runtime errors, you should always validate and sanitize your input, handle exceptions and errors gracefully, and use memory management and security best practices.
One other possibility to consider is adding some kind of logging to your code so that you can see some information about what was happening when a runtime error occurred. This can be particularly helpful when receiving error reports from users of the software, as associated logs may be able to point you in the right direction for fixing the error.
These types of errors hurt the most. Memory leaks can often cause your complete service to crash. You can avoid these by doing proper memory profiling and even setting up alerts for such crashes.
These errors are often hard to anticipate, but many of them can be caught in tests that anticipate lots of different input. In addition, get end users, other developers and stakeholders to run your code in non production or proof of concept environments and ask them to provide stack traces to any errors they encounter.
Os erros de tempo de execução ocorrem durante a execução do programa e geralmente são causados por condições imprevistas, como divisão por zero, acesso a uma posição inválida de memória ou estouro de pilha. Esses erros podem interromper a execução do programa ou causar comportamentos inesperados. Para evitar esses erros, é importante realizar verificações adequadas, como garantir que uma divisão não seja feita por zero ou verificar limites antes de acessar elementos de uma estrutura de dados.
Semantic errors are the most subtle and tricky type of programming errors, because they do not affect the functionality or performance of your code, but rather the meaning or intention of your code. Semantic errors occur when you use the wrong word, term, or concept in your code, such as confusing a parameter with an argument, a class with an object, or a method with a function. Semantic errors can lead to confusion, misunderstanding, or miscommunication among programmers, users, or clients, especially if you are working with multiple languages, frameworks, or libraries. To avoid semantic errors, you should always use clear and consistent naming conventions, document your code properly, and follow the domain-specific terminology and standards.
Semantic errors can be hard to fix by just reading the code. Often, line by line debugging (enabled by many IDEs) using break points is a great method to interrogate what your program is doing. You can track things like how the value of variables change, function calls and parameters provided, as well as output from things like REST requests.
Os erros semânticos ocorrem quando o código está gramaticalmente correto, mas não faz o que o programador pretendia. Esses erros podem resultar em comportamentos indesejados ou em resultados incorretos. Por exemplo, atribuir um valor incorreto a uma variável ou usar uma função de maneira inadequada podem ser considerados erros semânticos. Para evitar esses erros, é importante revisar cuidadosamente o código, entender os requisitos do problema e testar o programa com diferentes casos para garantir que os resultados sejam consistentes com as expectativas.
Style errors are the least critical but most common type of programming errors. They occur when you violate the best practices or guidelines for writing clean, readable, and maintainable code, such as using inconsistent indentation, spacing, or casing, using ambiguous or meaningless names, or writing too long or too complex code. Style errors do not affect the functionality or performance of your code, but they can affect the quality and readability of your code, making it harder to understand, debug, or modify. To avoid style errors, you should always follow the coding standards and conventions for your language, use descriptive and meaningful names, and refactor your code to make it simpler and more modular.
Programming errors are inevitable, but they can be avoided or minimized with good habits, tools, and techniques. By learning from your mistakes and improving your skills, you can write better code and become a better programmer.
I've found when working in a team it's good to agree on a set of code standards. Following a set style makes it easier for people to understand what a particular part of the code is doing when reading it for the first time. If you're writing code that looks completely different to what all your colleagues are writing, it will take them much longer to get a feel for your code, which makes code maintenance harder.
In a collaborative environment, it's important to have a coding style guide in place. This will make reading, reviewing and extending code much easier. If the project or the team is new, a style guide can be decided and agreed by all from the beginning (eg. by voting)
One time, it took me 3 hours to solve a bug in my code. The bug was simply because of 2 files with the same names but in different directories with similar logic. I did the fix in one, but the other file still had the same bug. Best way to debug such things is to actually look on the complete path where the error was caught.
Don't be discouraged if you spend a long time debugging code to realise that the issue is fixed with a one line code change. This is more common than many people think. Finding where the issue stems from is often the hardest part of fixing a bug.
Mesmo quando você não está seguindo o TDD, faça código em pequenos incrementos executáveis, testáveis, verificáveis... As vezes isso parece uma perda de tempo quando já se tem a visão do produto final desejado, mas quando o produto estiver completo terá muito menos problemas de bugs e lógica. Além disso, o "raciocínio modular" pode te levar a soluções melhores, mais simples ou mais robustas que a solução visualizada inicialmente.